Just go to Geeks.com and buy an APower psu for half the price of the "name" brands. I own 4 of them (500, 640, 800 and 900watt), and they are of great quality and have never failed me yet.
Don't listen to the hype or marketing schemes.
The AcBel built Cooler Master eXtreme Power 500w is certainly one of the older and lower end designs in today's roundup and as such it really isn't surprising that it is not the top unit today. While the unit was able to output its claimed capacity at 45c (and at 100v AC input) it was not a great unit or even a passing unit as the DC Output Quality was just plain bad at full load. The unit’s component selection and build quality are far from top notch, the efficiency peaked at ~77% and bottomed out at ~71%. The DC Output Quality was out of specification limits at full load on ALL of the rails at 100v. At the current price of $49.99 the eXtreme Power 500w is certainly not an “eXtremely” amazing buy as it did not cleanly pass testing.